The Bullwhip Effect is a supply chain phenomenon that occur when order size variability is (increased, decreased) as orders move in the supply chain from the retailer to the manufacturer and its suppliers.

increased/amplified

As you go up a supply chain, demand (increases, decreases) in variability.

increases

The longer the lead times, the more (certain, uncertain) demand is and the (less, more) safety stock is held.

uncertain; more

Business (often, rarely) buy before they need to, and in (smaller, larger) amounts, because suppliers offer pricing advantages.